Storable rack assembly

Abstract

A storable rack assembly to be used to drive a paper stop of a buckle-type sheet folding pan includes a perforate reversed crown extension spring attached at its outer end to the paper stop while the opposite end thereof is coiled within a housing. A rotatable sprocket located outside of the housing meshes with perforations in the reversed-crown extension spring to drive the spring and thereby move the paper stop. An indicator mechanism for indicating the amount of movement of the paper stop includes an indicator sprocket, which rotates with the rotatable sprocket and meshes with apertures in an indicator steel band. The storable rack assembly is mounted on a bias bar which, in turn, is pivotally mounted on the fold pan.

The embodiments of the invention in which an exclusive property or privilege are claimed are defined as follows: 
     
       1. A rack-and-pinion type linkage system for converting rotary motion into linear motion and thereby moving an object along a linear path said rack-and-pinion type linkage system comprising: a rack housing, said rack housing defining a chamber, said rack housing further defining a guiding surface located outside, but adjacent to, said chamber and being tangentially disposed to said chamber;   a crown extension spring being unattached to supporting structure along its length, said crown extension spring having a linear extended portion projecting outside said chamber across said guiding surface and being attached to said object at an outer end portion thereof only, and a stored, coiled, portion located in said chamber, said crown extension spring having a series of apertures longitudinally disposed therealong;   a pinion assembly comprising a gear means rotatably mounted on said housing adjacent said guiding surface, but on the opposite side of said spring extended portion from said guiding surface, for driving said crown extension spring, said gear means having teeth which mesh with said apertures; and   a drive means linked to said gear means for rotating said gear means in either of opposite selected directions in response to application of an external force to said drive means, thereby linearly moving said crown-extension-spring extended portion, along with said attached object and selectively coiling and uncoiling said crown-extension-spring coiled portion.   
     
     
       2. A rack-and-pinion type linkage system as claimed in claim 1 wherein is further included an indicating means linked to said gear, said indicating means including a measuring scale which moves proportionately to the rotation of said gear and including indicia thereon for indicating the extent to which the crown-extension-spring linear extended portion projects outside said chamber. 
     
     
       3. A rack-and-pinion type linkage system as claimed in claim 2 wherein: said indicator includes an indicator drive gear which is linked to, and rotates with, said rotatable gear; and   said scale means comprises an elongated indicating band having apertures therein which mesh with said indicator drive gear, said elongated band having said indicating indicia thereon;   whereby, as said rotatable gear is rotated said indicator drive gear is also rotated and moves said indicating band longitudinally to indicate the extent to which said crown extension spring is coiled and uncoiled.   
     
     
       4. A rack-and-pinion type linkage system as claimed in claim 1 wherein said drive means comprises a manual knob.